The number of concertos for guitar and orchestra is not long; the list of those heard regularly in concert halls is shorter still. This week, a Baltimore-rooted guitar concerto will enter the repertoire and, given the considerable assets behind it, should have a good chance of becoming one of the more successful works of its kind.

Jonathan Leshnoff, a rising figure in the contemporary music world and a Towson University faculty member, is the composer. He has written the concerto for and dedicated it to prominent classical guitarist and longtime Peabody Conservatory faculty member Manuel Barrueco, who will be the soloist for the premiere, backed by the Baltimore Symphony Orchestra and music director Marin Alsop.

The BSO, which first performed a piece by Leshnoff in 2010, commissioned his Guitar Concerto a year later. The Nashville Symphony, Reno Philharmonic and an orchestra in Spain joined the project as co-commissioners, guaranteeing more performances of the piece over the next few seasons.

Leshnoff has written several orchestral works (his Symphony No. 2 is due to be premiered next season by the Atlanta Symphony); a couple of oratorios and other vocal works; multiple chamber pieces; and seven concertos. But, until receiving the BSO commission in 2011, he had never composed anything for the guitar.

"I will go on record and say that the guitar is the hardest instrument to write for, even harder than the harp," Leshnoff says with a laugh.

Adds Barrueco: "Jonathan needed to find his way. He has been very smart, very quick. He has written a very effective piece."

The concerto has a traditional structure. After a tense opening, the first movement becomes lively; the finale is even livelier. In between is a soft, slow movement. A theme stated by the guitar at the beginning of the piece returns, in various guises, in each movement.

As his other works make clear, Leshnoff's style is grounded in tonality, but with plenty of distinctive harmonic spice, along with a keen rhythmic pulse. He made that rhythmic element especially pronounced while writing a concerto for an instrument most deeply associated with Spain.

"Of course, there's a Latin dance in the finale," Leshnoff, 40, says. "I had to put in some flamenco stuff. It's fun."

The composer, an Orthodox Jew, is at his most personal in the slow movement, which has a Hebrew letter, "vav," and a Hebrew word, "Hod," at the head of the score.

"This comes out of the Jewish mystical tradition," Leshnoff says, "and has to do with humility. It's about how everyone knows their place. In this movement, the winds and brass are out. The thinned-out orchestration lets the guitar sing."

To make sure that he was writing idiomatically for the solo instrument, Leshnoff would ask an assistant at Towson University to play passages as soon as they were on paper. Then he would show the music to Barrueco.

Composer and guitarist met periodically as the concerto took shape; when they couldn't get together in person, they held discussions via Skype.

"We would go through it measure by measure," the composer says. "Every note became like a colossal debate — OK, I'm hamming it up, but there was a lot of discussion. There might be one note different when Manuel was done with it, maybe just be an octave lower, but it would always be better."

"Jonathan wanted the concerto to be very demanding for the instrument," says Barrueco, 61. "Sometimes he would show me a passage and I would tell him, 'This is not playable,' but then I'd come back home and find the right fingering to make it work. So I would say, 'I take it back.'"

The result is a concerto that, in the outer movements, gives the soloist a virtuosic workout.

"It's like a tour de force to play this piece," Barrueco says. "The music is constantly changing. It's asymmetrical. Even when things seem to be the same, there's always a slight variation. It's more complicated than it sounds."

Before starting on the concerto project, Leshnoff immersed himself in guitar music by two 20th-century masters, Brazil's Heitor Villa-Lobos and Spain's Joaquin Rodrigo, whose "Concierto de Aranjuez" has been one of the most popular guitar concertos of the past 70 years.

"Rodrigo was a genius," Leshnoff says. "He knew that the guitar can do so much — every instrument likes to do some things and hates to do other things — and that the orchestra wants to do so much. He knew how to get the right balance between them."

Barrueco will help ensure a proper balance for the premiere. Classical guitarists are typically amplified when performing in large venues. Barrueco brings his own sound system.

"Amplification becomes, in effect, an extension of the instrument," he says. "It's important that everyone hears the piece and it's important how the notes sound. I'm all about the end result, the beauty of it."

Composer and soloist will get their first opportunity to experience the concerto in its intended state at the first rehearsal this week — they've only had a computer-generated approximation of the orchestral parts to listen to until now.

"I'm very curious how it's going to sound," Barrueco says. "I think it's going to sound very colorful. And I think people are going to like it very much."

The BSO performs Jonathan Leshnoff's Guitar Concerto on a program that includes works by Barber and Dvorak at 8 p.m. Thursday and 3 p.m. Jan. 12 at Meyerhoff Symphony Hall, 1212 Cathedral St. Tickets are $39 to $75. Call 410-783-8000, or go to bsomusic.org.

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